title: Tocotrienol prevents AAPH-induced neurite degeneration in neuro2a cells.
abstract: OBJECTIVE
  Reactive oxygen species induce neurite degeneration before inducing cell death. However, the degenerative mechanisms have not yet been elucidated. While tocotrienols have a known neuroprotective function, the underlying mechanism remains unclear and may or may not involve antioxidant action. In this study, we hypothesize that free radical-derived membrane injury is one possible mechanism for inducing neurite degeneration. Therefore, we examined the potential neuroprotective effect of tocotrienols mediated through its antioxidant activity.
  
  
  METHODS
  Mouse neuroblastoma neuro2a cells were used to examine the effect of the water-soluble free radical generator 2,2'-azobis(2-methylpropionamide) dihydrochloride (AAPH) on neurite dynamics. After 24 hours of AAPH treatment, cell viability, neurite number, and the number of altered neurites were measured in the presence or absence of α-tocotrienol.
  
  
  RESULTS
  Treatment of neuro2a cells with a low concentration of AAPH induces neurite degeneration, but not cell death. Treatment with 5 µM α-tocotrienol significantly inhibited neurite degeneration in AAPH-treated neuro2a cells. Furthermore, morphological changes in AAPH-treated neuro2a cells were similar to those observed with colchicine treatment.
  
  
  CONCLUSIONS
  α-Tocotrienol may scavenge AAPH-derived free radicals and alkoxyl radicals that are generated from AAPH-derived peroxyl radicals on cell membranes. Therefore, α-tocotrienol may have a neuroprotective effect mediated by its antioxidant activity.
authors.affiliation: Shibaura Institute of Technology, Fukasaku 307, Minuma-ku, Saitama 337-8570, Japan; Shibaura Institute of Technology, Saitama 337-8570, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Fukui
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Sekiguchi
authors.forename: Hirokatsu
authors.initials: H
authors.lastname: Takatsu
authors.forename: Taisuke
authors.initials: T
authors.lastname: Koike
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Koike
authors.forename: Shiro
authors.initials: S
authors.lastname: Urano
mesh_terms: D000578:Amidines / Q000037:antagonists & inhibitors / Q000633:toxicity*; D000818:Animals; D016923:Cell Death / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003078:Colchicine / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology; D051379:Mice; D016501:Neurites / Q000187:drug effects* / Q000648:ultrastructure; D018696:Neuroprotective Agents / Q000494:pharmacology*; D024508:Tocotrienols / Q000494:pharmacology*
chemical_list: D000578:Amidines; D016166:Free Radical Scavengers; D018696:Neuroprotective Agents; D024508:Tocotrienols; C046728:2,2'-azobis(2-amidinopropane); C082032:tocotrienol, alpha; D003078:Colchicine